This grant will establish the Temple University Center for Adolescent Substance Abuse and HIV Implementation Research (TUCAIR) to carry out the goals of the Translational Research on Interventions for Adolescents in the Legal System (TRIALS) cooperative agreement. The goals are to develop and test implementation strategies to improve the continuum of HIV prevention and treatment and substance abuse and services for youth under community juvenile justice supervision. Juvenile offenders are at high risk for HIV and other STDs and much of that risk is related to their substance abuse. We will (1) identify, develop and refine a set of measures to assess existing HIV/other STDs and substance abuse services as well as environmental, interagency, organizational, and individual factors that may facilitate or impede effective delivery of these services, as well as implementation outcomes; (2) implement those measures in our partner juvenile justice and service provider agencies; and (3) design and test one or more data-driven multisite implementation interventions to address service gaps, particularly in HIV and other STD prevention and treatment interventions. TUCAIR includes a team of researchers with extensive expertise in juvenile justice; HIV/other STD prevention, education, and treatment; substance abuse prevention and treatment; implementation science; and fielding multisite research protocols. TUCAIR will work with juvenile justice, public health, and community-based service agency partners in six diverse jurisdictions, including three counties in Pennsylvania, two in Florida, and the District of Columbia, ensuring access to ample staff and adolescent subjects to achieve the goals of TRIALS. TUCAIRs primary juvenile justice research partnership will be with the FL Department of Juvenile Justice, 13th Circuit, which operates juvenile probation in Hillsborough County. PI Belenko has a long history of collaborative research with Hillsborough County agencies through subcontract PI Dembo and the University of South Florida; these collaborations have specifically addressed HIV/STD service needs and the improvement of access to prevention and treatment for youths in the juvenile justice system. Our proposed research concept describes the teams approach to implementation research under TRIALS and presents our conceptual model for guiding study measures, design, and analyses. This research will increase our knowledge of how juvenile justice systems can more effectively implement a continuum of evidence-based HIV/STD prevention and treatment and related substance abuse services to young offenders under community supervision, and make important contributions to public health and implementation science.